1. Field of the Invention
The present invention relates to a washing nozzle with jetting holes for jetting jet streams of wash water to tableware set in a washing chamber of a dishwashing machine while being rotated. In particular it relates to a washing nozzle through which the wash water can be widely jetted to the tableware positioned at four corners of a rack for setting tableware therein, thereby the tableware can be efficiently washed.
2. Description of Related Art
Conventionally, have been proposed various washing nozzles utilized in a dishwashing machine. Such washing nozzles are classified in two types according to washing manner. One is a fixed type and the other is a rotating type.
Here, the fixed type is constructed from a washing nozzle which is fixedly arranged in a wash chamber, wash water is jetted from jetting holes formed in the washing nozzle to tableware set in a rack, thereby the tableware is washed. The rotating type is constructed from a washing nozzle which washes the tableware set in the rack by jetting the wash water to the tableware while being rotated, the washing nozzle being rotated by horizontal component force of reactive jetting force yielded when the wash water is jetted from the jetting holes.
In the fixed type, since the washing nozzle is fixed in the wash chamber, are degraded jetting force and jetting angle of the wash water are degraded due to shape of the tableware to be washed (for instance, in case that the tableware has a shape of bowl), unless an arranging position of the washing nozzle or forming positions of the jetting holes in the washing nozzle is suitably decided. And similarly, maintenance of the dishwashing machine such as change of a filter arranged in a wash water tank cannot be easily conducted since the washing nozzle is fixed in the wash chamber. Thus, running cost cannot be reduced in the dishwashing machine utilizing the washing nozzle of the fixed type.
On the other hand, the rotating type is widely used in the various dishwashing machines based on a reason that the rotating washing nozzle washes the tableware by jetting the wash water from the jetting holes to the tableware while rotating and the above mentioned problems in the fixed type scarcely occurs. For example, as such rotating washing nozzle, a washing nozzle shown in FIGS. 8, 9 is conventionally utilized in the dishwashing machine.
Here, the conventional rotating washing nozzle will be described hereinafter referring to FIGS. 8 and 9. FIG. 8 is a plan view of the washing nozzle and FIG. 9 is a side view of the washing nozzle, in which a part of the nozzle is sectioned.
A rotating washing nozzle 50 is constructed from a pair of nozzle members 51 (upper nozzle member) and 52 (lower nozzle member), each of the nozzle members 51, 52 being pressed into a predetermined shape as shown in FIGS. 8, 9 and combined into one body by calking. A support part 53 is formed on a central position of the washing nozzle 50 and this support part 53 is rotatably supported at an end portion of a pipe (not shown) for providing wash water to the washing nozzle 50, thereby the washing nozzle 50 becomes rotatable at the end portion of the pipe.
On the upper surface of the upper nozzle member 51, a plurality of evaginated portions 54 are formed (for example, eight of the evaginated parts 54 are formed in FIGS. 8 and 9). And a pair of jetting holes 55 are opened on each of the evaginated parts 54. Further, among four evaginated parts 56 formed near the support part 53, on each of two evaginated parts 56 being opposed with each other, a jetting hole 57 is opened, respectively.
In the above washing nozzle 50, when the wash water is provided with the washing nozzle 50 from the pipe for providing the wash water, the wash water is jetted to the dirty tableware set in the rack (not shown) from the jetting holes 55, 57 and the dirty tableware is washed. At that time, the washing nozzle 50 is rotated around the support part 53 by the horizontal component force of the reactive jetting force yielded when the wash water is jetted from the jetting holes 55, 57 and the washing nozzle 50 washes the tableware while rotating thereof.
However, in the dishwashing machine adopting the rotating washing nozzle 50 mentioned above, the wash water is jetted to the tableware set in the Pack from the jetting holes 55, 57 while the washing nozzle 50 is rotated and therefore, blind spots (where the wash water is not jetted) are, in general, apt to occur at four corners in the rack. As a result, there is a problem that the tableware set at the four corners in the rack cannot be effectively washed. Further, in the washing nozzle 50, jettable range of the wash water jetted from the jetting holes 55 opened on the evaginated parts 54 formed on both ends of the washing nozzle 50, is very narrow as shown by arrows in FIG. 10. Thus, it will be possible that the tableware set at the four corners in the rack cannot be effectively washed.
In order to avoid the above problems, the large jetting holes 55 which cover wide jetting area are opened on the evaginated parts 54 at both ends of the washing nozzle 50 and thereby the tableware set at the four corners (blind spots) in the rack are washed.
However, in that case, plenty of the wash water is jetted from the jetting holes 55. Therefore, for instance, in case that such washing nozzle 50 is utilized as the lower nozzle in the wash chamber, the tableware such as cups in the rack, which are formed of synthesized polymer and thus comparatively light, will be upset due to the tableware being lifted by strong jetting force of the wash water jetted from the large jetting holes 55. If the tableware is upset, the wash water is gathered in the tableware and, as a result, the tableware cannot be effectively washed. In addition to the above, rinsing of the washed tableware cannot be effectively conducted if the tableware is upset. Further, when the tableware is disturbed by the strong force of the jetted wash water from the jetting holes 55, the tableware is collided with each other and thus broken.